In purely electrically driven motor vehicles, such as battery electrical vehicles (BEV) or fuel cell vehicles, multiple drive units are often provided on different axles. In each of the drive units, the same power electronics with Si power semiconductors is used.
Today's vehicles still have a relatively low range and the costs for the HV battery are high. Therefore, the present invention has established the object of making available a drive system which can achieve a predetermined range with lower battery capacity and with no power losses.
The efficiency of power electronic components can be increased significantly by using, instead of silicon-based semiconductor components, components based on silicon carbide (SiC).
US 2015/246614 A1 discloses an inductive energy transfer system built into a roadway. It is possible to use silicon carbide semiconductor components in the unit supplying the induction coils in order to switch the currents flowing through the induction coils.
Known from DE 10 2016 207 254 A1 are an inverter for the providing of phase currents for an electric machine and an electrical drive arrangement for a hybrid electric vehicle/electric vehicle with such an inverter. The inverter comprises a conduction switch, designed as a silicon carbide semiconductor switch, which closes automatically when the control signal is cut off. The conduction switch may be a MOSFET or IGBT.
Originating from WO 2016/002057 A1 is a silicon carbide semiconductor component that can be used in a power module, an inverter, and a three-phase motor system for an electric vehicle.
Thanks to a traction inverter based on SiC (SiC inverter), a savings of up to approximately 0.5 kWh/100 km can be achieved in a vehicle with a drive in the WLTP cycle (Worldwide Harmonized Light-Duty Vehicles Test Procedure) or NEFZ cycle (New European Driving Cycle according to directive 70/220/EWG). For a vehicle range of 500 km, this enables a lowering of the battery capacity by around 2.5 kWh.
In the normal driving mode of a vehicle with two electrical drive units, one drive unit is chiefly under load and the other one is merely entrained with it. Only when there is a torque demand that the first drive unit alone cannot satisfy is the second drive unit additionally switched in. The torque distribution between the drive units is primarily shifted to one drive unit, for reasons of efficiency.